th.header {
    background-image: url(../images/bg.gif);  
	background-repeat: no-repeat;
	background-position: right center;
}

th.headerSortUp {
    background-image: url(../images/asc.gif);  
	background-repeat: no-repeat;
	background-position: right center;
}

th.headerSortDown { 
    background-image: url(../images/desc.gif);
	background-repeat: no-repeat;
	background-position: right center;
} 